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Proserpinaca pectinata — comb-leaved mermaid-weed

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New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Facts

Comb-leaved mermaid-weed is primarily a species of the coastal plain, though a few populations occur in similar habitats (edges of ponds, pools, ditches) further inland. At the northern limit of its range in Maine and New Hampshire, comb-leaved mermaid-weed is rare.

Habitat

Anthropogenic (man-made or disturbed habitats), shores of rivers or lakes

Characteristics

Habitat
  • aquatic
  • wetlands
New England state
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
Flower petal color
NA
Leaf type
the leaves are simple (lobed or unlobed but not separated into leaflets)
Leaf arrangement
alternate: there is one leaf per node along the stem
Leaf blade edges
the edge of the leaf blade has lobes, or it has both teeth and lobes
Flower symmetry
there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
Number of sepals, petals or tepals
there are three petals, sepals, or tepals in the flower
Stamen number
3
Fruit type (general)
the fruit is dry but does not split open when ripe
Fruit length
2–2.8 mm
Show all characteristics

  • Clonal plantlets

    Bulbils
    the plant does not appear to have bulbils
    Bulblets replace flowers
    there are no bulblets where the flowers are located

  • Flowers

    Anther opening
    the anthers have narrow slits or furrows that run lengthwise along the anthers
    Anther spurs
    the anthers do not have spurs on them
    Calyx growth after flowering
    the calyx grows to cover or partially cover the fruit
    Calyx symmetry
    there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
    Carpels fused
    the carpels are fused to one another
    Cilia on petals
    NA
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    Corolla morphology
    NA
    Corolla palate
    NA
    Corona lobe length
    0 mm
    Epicalyx
    the flower does not have an epicalyx
    Epicalyx number of parts
    0
    Filament surface
    the filament is smooth, with no hairs or scales
    Flower description
    the flower has an inferior ovary, with or without a hypanthium
    Flower petal color
    NA
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Flowers sunken into stem
    no
    Form of style
    the style is narrow at the tip and unbranched
    Fringed petal edges
    NA
    Fused stamen clusters
    NA
    Horns in hoods (Asclepias)
    NA
    Hypanthium
    the flower does not have a hypanthium
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inner tepals (Rumex)
    NA
    Length of flower stalk
    0 mm
    Length of peduncle
    0 mm
    Marks on petals
    NA
    Nectar spur
    the flower has no nectar spurs
    Number of carpels
    3
    Number of pistils
    3
    Number of sepals, petals or tepals
    there are three petals, sepals, or tepals in the flower
    Number of styles
    3
    Ovary position
    the ovary is below the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes only one cycle of petals or sepals
    Petal appearance
    NA
    Petal base
    NA
    Petal glandular dots or scales
    NA
    Petal hairs (Viola)
    NA
    Petal hairs on inner/upper surface
    NA
    Petal length
    0 mm
    Petal length relative to sepals
    NA
    Petal nectaries
    NA
    Petal number
    0
    Petal shape
    NA
    Petal tip shape
    NA
    Petal tips (Cuscuta)
    NA
    Petal width
    0 mm
    Raceme attachment (Veronica)
    NA
    Scales inside corolla
    NA
    Sepal and petal color
    the petals and sepals are similar
    Sepal appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal color
    • blue to purple
    • green to brown
    Sepal number
    3
    Sepal shape
    the sepal outline is roughly triangular
    Stamen number
    3
    Stamen position relative to petals
    the stamens are lined up with the sepals
    Staminodes
    there are no staminodes on the flower
    Style petal-like
    the styles are not petal-like
    Umbel flower reproductive parts
    NA
    Upper lip of bilabiate corolla
    NA

  • Fruits or seeds

    Achene surface (Polygonum)
    NA
    Berry color
    NA
    Capsule color (Viola)
    NA
    Capsule ribs
    NA
    Capsule splitting
    NA
    Fruit (pyxis) dehiscence
    NA
    Fruit beak length
    0 mm
    Fruit features (Brassicaceae)
    NA
    Fruit length
    2–2.8 mm
    Fruit locules
    three
    Fruit shape
    conical
    Fruit type (general)
    the fruit is dry but does not split open when ripe
    Fruit type (specific)
    • the fruit is a drupe (fleshy, with a firm inner ovary wall that encloses a single seed)
    • the fruit is a nut (dry and indehiscent, with a hard wall, usually containing only one seed and usually subtended by an involucre)
    • the fruit is a schizocarp (when dry it splits into sections, each holding one or more seeds)
    Legumes (Fabaceae)
    NA
    Mericarp length
    0 mm
    Mericarp segment shape (Desmodium)
    NA
    Other markings on berry
    NA
    Ovary stipe
    the ovary or fruit does not have a stipe
    Placenta arrangement
    the plant has apical placentation, where one or a few ovules develop at the top of a simple or compound ovary
    Rows of seeds in fruit (Brassicaceae)
    NA
    Schizocarpic fruit compression
    NA
    Schizocarpic fruit segments
    0
    Seed number
    3
    Septum in fruit (Brassicaceae)
    NA
    Wings on fruit
    the fruit does not have wings on it
    prickles on fruits
    the fruits do not have thorn-like defensive structures

  • Glands or sap

    Glands on leaf blade
    the leaf blades do not have glandular dots or scales
    Sap
    the sap is clear and watery
    Sap color
    the sap is clear

  • Growth form

    Growth form
    the plant is an herb (it has self-supporting stems)
    Lifespan
    the plant lives more than two years
    Parasitism
    the plant is not parasitic
    Plant color
    the leaves or young stems of the plant are green
    Spines on plant
    the plant has no spines
    Underground organs
    the plant has a rhizome (a horizontal underground stem with roots growing from it)

  • Leaves

    Bracteole number (Apiaceae)
    0
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length (compound lvs only)
    2–7.5 mm
    Floral bracts
    the flower has one or more bracts associated with it
    Hairs on underside of leaf
    the underside of the leaf is not hairy, or it has very few hairs
    Hairs on upper side of leaf
    the upper side of the leaf is not hairy, or it has very few hairs
    Hooked hairs on underside of leaf
    no
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade base
    the leaf has a distinct leaf stalk (petiole)
    Leaf blade edges
    the edge of the leaf blade has lobes, or it has both teeth and lobes
    Leaf blade hairs
    NA
    Leaf blade length
    13–23 mm
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade texture
    the leaf blade is coriaceous (has a firm, leathery texture)
    Leaf duration
    the leaves drop off in winter (or they whither but persist on the plant)
    Leaf form
    the leaves are green, with an expanded blade and a leaf-like texture
    Leaf hair orientation
    NA
    Leaf spines
    there are no spines on the leaf edges
    Leaf stalk
    the leaves have leaf stalks
    Leaf teeth and lobes
    the leaf has a row of two or more lobes on each side of the central axis
    Leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Leaf variation
    the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
    Leaves per node
    there is one leaf per node along the stem
    Specific leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Stipule edges
    NA
    Stipule features
    NA
    Stipule fused to leaf stalk
    NA
    Stipule shape
    NA
    Stipules
    there are no stipules on the plant
    Teeth per side of leaf blade
    0

  • Place

    Habitat
    • aquatic
    • wetlands
    New England state
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • man-made or disturbed habitats
    • shores of rivers or lakes

  • Scent

    Plant odor
    the plant does not have much of a smell

  • Stem, shoot, branch

    Branched tendrils
    NA
    Hooked hairs on stem between nodes
    no
    Plant height
    Up to 50 cm
    Stem orientation
    the stems trail at the base, but may turn upwards at the tips
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England distribution and conservation status

Distribution

Connecticut
absent
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Maine
extremely rare (S-rank: S1), endangered (code: E)
Massachusetts
unranked (S-rank: SNR)
New Hampshire
historical (S-rank: SH), endangered (code: E)
Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)

Native to North America?

Yes

Sometimes confused with

Proserpinca palustris

Family

Haloragaceae

Genus

Proserpinaca

Help

From the dichotomous key of Flora Novae Angliae

2.  Proserpinaca pectinata Lam. N

comb-leaved mermaid-weed. MA, ME, NH, RI; mainly along the coastal plain. Pond shores, pools, ditches, wet, peaty depressions. In southwestern ME and eastern NH this species occurs inland from the coastal plain. However, those areas harbor ponds that are hydrologically and/or floristically similar to coastal plain pond shores.

1×2. Proserpinaca palustris × Proserpinaca pectinata → Proserpinaca ×‌intermedia Mackenzie is a rare mermaid-weed hybrid known from MA, RI. It can be recognized by the pinnately lobed submsersed leaves with 7–12 pairs of divisions 2–3.5 mm long. Proserpinaca ×‌intermedia is further characterized by leaves with a central rachis 1–4 mm wide (vs. 0.2–1 mm in P. pectinata) and fruits 2.3–3.6 mm wide.